Subclass of Zlib::Error
When zlib returns a Z_STREAM_ERROR, usually if the stream state was inconsistent.
Zlib::ZStream
is the abstract class for the stream which handles the compressed data. The operations are defined in the subclasses: Zlib::Deflate
for compression, and Zlib::Inflate
for decompression.
An instance of Zlib::ZStream
has one stream (struct zstream in the source) and two variable-length buffers which associated to the input (next_in) of the stream and the output (next_out) of the stream. In this document, “input buffer” means the buffer for input, and “output buffer” means the buffer for output.
Data
input into an instance of Zlib::ZStream
are temporally stored into the end of input buffer, and then data in input buffer are processed from the beginning of the buffer until no more output from the stream is produced (i.e. until avail_out
> 0 after processing). During processing, output buffer is allocated and expanded automatically to hold all output data.
Some particular instance methods consume the data in output buffer and return them as a String
.
Here is an ascii art for describing above:
+================ an instance of Zlib::ZStream ================+ || || || +--------+ +-------+ +--------+ || || +--| output |<---------|zstream|<---------| input |<--+ || || | | buffer | next_out+-------+next_in | buffer | | || || | +--------+ +--------+ | || || | | || +===|======================================================|===+ | | v | "output data" "input data"
If an error occurs during processing input buffer, an exception which is a subclass of Zlib::Error
is raised. At that time, both input and output buffer keep their conditions at the time when the error occurs.
Method
Catalogue Many of the methods in this class are fairly low-level and unlikely to be of interest to users. In fact, users are unlikely to use this class directly; rather they will be interested in Zlib::Inflate
and Zlib::Deflate
.
The higher level methods are listed below.
Zlib::GzipWriter
is a class for writing gzipped files. GzipWriter
should be used with an instance of IO
, or IO-like, object.
Following two example generate the same result.
Zlib::GzipWriter.open('hoge.gz') do |gz| gz.write 'jugemu jugemu gokou no surikire...' end File.open('hoge.gz', 'w') do |f| gz = Zlib::GzipWriter.new(f) gz.write 'jugemu jugemu gokou no surikire...' gz.close end
To make like gzip(1) does, run following:
orig = 'hoge.txt' Zlib::GzipWriter.open('hoge.gz') do |gz| gz.mtime = File.mtime(orig) gz.orig_name = orig gz.write IO.binread(orig) end
NOTE: Due to the limitation of Ruby’s finalizer, you must explicitly close GzipWriter
objects by Zlib::GzipWriter#close
etc. Otherwise, GzipWriter
will be not able to write the gzip footer and will generate a broken gzip file.
The InstructionSequence
class represents a compiled sequence of instructions for the Virtual Machine used in MRI. Not all implementations of Ruby may implement this class, and for the implementations that implement it, the methods defined and behavior of the methods can change in any version.
With it, you can get a handle to the instructions that make up a method or a proc, compile strings of Ruby code down to VM instructions, and disassemble instruction sequences to strings for easy inspection. It is mostly useful if you want to learn how YARV works, but it also lets you control various settings for the Ruby iseq compiler.
You can find the source for the VM instructions in insns.def
in the Ruby source.
The instruction sequence results will almost certainly change as Ruby changes, so example output in this documentation may be different from what you see.
Of course, this class is MRI specific.
HTTPGenericRequest
is the parent of the Net::HTTPRequest
class. Do not use this directly; use a subclass of Net::HTTPRequest
.
Mixes in the Net::HTTPHeader
module to provide easier access to HTTP headers.
An implementation of PseudoPrimeGenerator
which uses a prime table generated by trial division.
Internal use. An implementation of prime table by trial division method.
Defines an Element
Attribute
; IE, a attribute=value pair, as in: <element attribute=“value”/>. Attributes
can be in their own namespaces. General users of REXML
will not interact with the Attribute
class much.
A class that defines the set of Attributes
of an Element
and provides operations for accessing elements in that set.
Represents an XML
Instruction
; IE, <? … ?> TODO: Add parent arg (3rd arg) to constructor
Certain attributes are required on specific tags in an RSS
feed. If a feed is missing one of these attributes, a MissingAttributeError
is raised.
A test case for Gem::Installer
.
The UriParser
handles parsing URIs.
Gem::StreamUI
implements a simple stream based user interface.
Used to construct C classes (CUnion
, CStruct
, etc)
Fiddle::Importer#struct
and Fiddle::Importer#union
wrap this functionality in an easy-to-use manner.
Numeric
is the class from which all higher-level numeric classes should inherit.
Numeric
allows instantiation of heap-allocated objects. Other core numeric classes such as Integer
are implemented as immediates, which means that each Integer
is a single immutable object which is always passed by value.
a = 1 1.object_id == a.object_id #=> true
There can only ever be one instance of the integer 1
, for example. Ruby ensures this by preventing instantiation. If duplication is attempted, the same instance is returned.
Integer.new(1) #=> NoMethodError: undefined method `new' for Integer:Class 1.dup #=> 1 1.object_id == 1.dup.object_id #=> true
For this reason, Numeric
should be used when defining other numeric classes.
Classes which inherit from Numeric
must implement coerce
, which returns a two-member Array
containing an object that has been coerced into an instance of the new class and self
(see coerce
).
Inheriting classes should also implement arithmetic operator methods (+
, -
, *
and /
) and the <=>
operator (see Comparable
). These methods may rely on coerce
to ensure interoperability with instances of other numeric classes.
class Tally < Numeric def initialize(string) @string = string end def to_s @string end def to_i @string.size end def coerce(other) [self.class.new('|' * other.to_i), self] end def <=>(other) to_i <=> other.to_i end def +(other) self.class.new('|' * (to_i + other.to_i)) end def -(other) self.class.new('|' * (to_i - other.to_i)) end def *(other) self.class.new('|' * (to_i * other.to_i)) end def /(other) self.class.new('|' * (to_i / other.to_i)) end end tally = Tally.new('||') puts tally * 2 #=> "||||" puts tally > 1 #=> true